
The origin of iodine
Iodine was first discovered in 1811 by the French chemist Bernard Courtois while extracting compounds from seaweed. He accidentally produced purple vapor by adding an excessive amount of sulfuric acid, which then condensed into a solid form and was named iodine. A year later, Joseph Louis Gay-Lussac demonstrated that this substance was an independent element with properties similar to chlorine and named it “iodine” after the Greek word “iodes,” meaning violet. Shortly afterward, industrial production of iodine began, and since 1816, its use as a disinfectant, followed by applications in pharmaceuticals and various industries, expanded.
Iodine was discovered in 1811 by the French chemist Bernard Courtois. Courtois was extracting sodium and potassium compounds from seaweed ash. After separating these compounds, he added sulfuric acid (H₂SO₄) to continue processing the ash. However, he accidentally added an excessive amount of acid, which caused a purple vapor to be released from the mixture. This gas condensed on metal objects in the room, forming solid iodine. Courtois entrusted the investigation of this substance to a friend, who published the research findings in 1813. This marked the beginning of iodine’s history.
A year later, Joseph Louis Gay-Lussac in France recognized that this substance was an element with properties similar to chlorine and named it “iodine,” derived from the Greek word “iodes,” meaning violet. In the same year, industrial production of iodine began. By 1816, iodine was reported to be used as a disinfectant in pharmaceutical products. Subsequently, iodine found widespread applications not only in pharmaceuticals but also across various industrial fields.